JP3255041B2 - Surface-coated cermet cutting tools with excellent fracture resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention, aluminum oxide which constitutes the hard coating layer (hereinafter, Al ₂ O indicated by ₃₎ relates to an improvement of the layer, which the layer thickness be thickened is uniform, and It has excellent interlayer adhesion, so it can be used not only for continuous cutting of steel and cast iron, for example, but also for intermittent cutting, without any chipping or chipping (small chipping). The present invention relates to a surface-coated cermet cutting tool (hereinafter, referred to as a coated cermet tool) that exhibits excellent cutting performance over a wide range.

[0002]

2. Description of the Related Art Conventionally, a titanium carbide (hereinafter, referred to as TiC) layer and a nitride (hereinafter, also referred to as T) are provided on a surface of a titanium carbonitride-based cermet substrate (hereinafter, referred to as a cermet substrate).
iN) layer, carbonitride (hereinafter referred to as TiCN)
Layer, oxide (hereinafter referred to as TiO ₂ ) layer, carbonate (hereinafter referred to as TiCO) layer, nitride oxide (hereinafter referred to as TiNO) layer, and carbonitride oxide (hereinafter referred to as TiCNO) layer and one or more of Ti compound layer formed of, Al ₂ O ₃ layer, in configured hard coating layer 3 to 2
Coated cermet tools are known which are chemically and / or physically deposited with an average layer thickness of 0 μm. Further, in particular, Al ₂ constituting the hard coating layer of the coated cermet tool described above.
The O ₃ layer is composed of, as a reaction gas, aluminum trichloride (hereinafter referred to as AlCl ₃ ):
20%, carbon dioxide (hereinafter referred to as CO ₂ ): 0.5 to 30%, [If necessary, carbon monoxide (CO) or hydrogen chloride (H
Cl): 1 to 30%], hydrogen: residual, and a hydrogen-based reaction gas having a composition of: reaction temperature: 950 to 1100 ° C .; atmospheric pressure: 20 to 200 torr. ing.

[0003]

On the other hand, in recent years, the use of FA in cutting has been remarkable, and there has been a strong demand for labor saving. With this, a further extension of the service life of coated cermet tools has been required. As a corresponding measure,
Of the hard coating layer of the same, and more particularly excellent in oxidation resistance and thermal stability have been further thickening widely studied of the Al ₂ O ₃ layer having a high hardness, the the Al ₂ O ₃ layer Is
If the thickness is increased, the thickness of the conventional Al ₂ O ₃ layer forming means becomes locally non-uniform, and the flank of the cutting edge, the rake face, and the edge between the flank and the rake face intersect. This results in significant variations in the layer thickness, and in addition to insufficient interlaminar adhesion with other Ti compound layers constituting the hard coating layer, is used for intermittent cutting of steel or cast iron, for example. In such a case, chips such as chipping and chipping are liable to occur when the cutting blade is used.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above-described viewpoint, attention is paid to the Al ₂ O ₃ layer constituting the hard coating layer of the coated cermet tool, and when the thickness is increased, the local variation of the layer thickness is reduced, and the other constituent layers Ti
As a result of conducting research to improve the interlayer adhesion to the compound layer, the chemical vapor deposition
AlCl ₃ : 1 to 10%, Hydrogen (hereinafter referred to as H ₂ ): 1 to 5%, Nitrogen oxide (hereinafter referred to as NO): 16 to 30%, Titanium tetrachloride (hereinafter referred to as TiCl ₄ ) Shown): 0.05-
An Ar-based reaction gas having a composition of 0.7%, Ar: remaining, is used, and the reaction temperature and the atmospheric pressure are as follows: reaction temperature: 700 to 900 ° C., atmospheric pressure: 20 to 200 torr. When the layer is formed, the formed layer has an amorphous structure and the conventional hard coating layer of Al ₂ O ₃
Al ₂ O ₃ constituting the layer is a composition containing Ti, Cl, and N, that is, the main component is Al and oxygen (O);
It has a composition containing Ti, Cl, and N, and the content ratio of Ti and Cl is adjusted by adjusting the composition and reaction atmosphere of the above Ar gas-based reaction gas to obtain a weight percent. (% Represents% by weight (% by mass)), Ti: 1 to 15% and Cl:
When the content is set to 0.005 to 0.1%, the resulting Al—O-based amorphous layer containing Ti and Cl has a significant local variation in the layer thickness even if the thickness is increased. The flank of the cutting edge, the rake face, and the layer thickness of the edge portion where the flank and the rake face intersect each other become uniform, and in addition, the content ratio of N is also 0.001 to 0.001.
When the content is adjusted to 0.1%, the interlayer adhesion with the Ti compound layer constituting the hard coating layer is remarkably improved in the coexistence with Ti. Therefore, the Al—O-based amorphous layer and the T
The coated cermet tool obtained by forming a hard coating layer composed of an i-compound layer on the surface of a super-hard substrate is excellent because the Al-O-based amorphous layer has the same properties as the Al ₂ O ₃ layer. Combined with oxidation resistance, thermal stability, and high hardness, the cutting edge is chipped or chipped when used for interrupted cutting as well as continuous cutting of steel and cast iron, for example. Research results have shown that cutting performance is excellent over a long period of time without occurrence of such defects.

The present invention has been made on the basis of the above-mentioned research results, and a TiC layer, TiN layer, TN layer formed by chemical vapor deposition or physical vapor deposition on the surface of a cermet substrate.
AlCl ₃ : 1 to 10% by volume, and one or more of Ti compound layers including an iCN layer, a TiO ₂ layer, a TiCO layer, a TiNO layer, and a TiCNO layer.
_{2: 1~5%, NO: 16~30} %, TiCl 4: 0.
A having a composition of 0.5 to 0.7%, Ar: remaining
Al ₂ O ₃ is formed by chemical vapor deposition using an r-based reaction gas.
, Ti: 1 to 15%, Cl: 0.005 to 0.1%,
N: 0.001 to 0.1%, and a hard coating layer composed of an Al—O-based amorphous layer having an amorphous structure with an average thickness of 3 to 20 μm. The present invention is characterized in that the coated cermet tool has excellent fracture resistance.

As described above, Ti and Cl in the Al—O-based amorphous layer constituting the hard coating layer of the coated cermet tool according to the present invention, as described above, coexist in these two components and act to make the layer thickness uniform. Therefore, even if the content of Ti of these two components is less than 1% or the content of Cl is less than 0.005%, the desired effect cannot be obtained in the above-mentioned action. If the content of any of the above exceeds 15% of Ti and 0.1% of Cl, A
The properties of the Al—O-based amorphous layer having the same properties as the l ₂ O ₃ layer are impaired. From these results, the content was set to Ti: 1 to 15%, respectively.
Cl: 0.005 to 0.1%. Also, N
The component has the effect of improving the interlayer adhesion of the Al—O-based amorphous layer to the Ti compound layer in the coexistence with Ti as described above. Cannot improve the interlayer adhesion. On the other hand, if the content exceeds 0.1%, the properties of the Al—O-based amorphous layer will be impaired. ０．１0.1%. Furthermore, the reason why the average layer thickness of the hard coating layer is 3 to 20 μm is that the layer thickness is 3 μm
Cannot secure the desired excellent wear resistance,
On the other hand, if the layer thickness exceeds 20 μm, the chipping resistance is reduced.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the coated cermet tool of the present invention will be specifically described with reference to examples. As a raw material powder, (Ti _0.6 W _0.3 M having an average particle diameter of 1.3 μm)
o _0.1 ) CN powder, TiCN powder of 1.5 μm, TaC powder of 1.5 μm, NbC powder of 1.5 μm,
A 1.5 μm Mo ₂ C powder, a 2.0 μm Ni powder, and a 1.1 μm Co powder were prepared, and these raw material powders were blended in the composition shown in Table 1 and wet-processed in a ball mill for 72 hours. After mixing and drying, ISO ・ CNMG
Cermet substrates A and B were manufactured by press-molding a green compact having a shape defined by 120408 and sintering the green compact in vacuum under the same conditions as shown in Table 1. Table 1 shows the internal hardness (Rockwell hardness A scale) of each of the cermet substrates A and B.

Then, the surfaces of these cermet substrates A and B are honed, and a conventional chemical vapor deposition apparatus is used. Table 2 (1-TiCN in the table corresponds to JP-A-6-80)
Under the conditions shown in Table 3, the composition and the target layer thickness shown in Table 4 (the layer thickness at the flank of the cutting edge) were obtained under the conditions shown in Table 3. By forming a coating layer, coated cermet tools 1 and 2 of the present invention and conventional coated cermet tools 1 and 2 were manufactured, respectively. The resulting Al-O-based amorphous layer and Al constituting the hard coating layer of various coated cermet tools
Regarding the ₂ O ₃ layer (identification of these layers was performed by observing the X-ray diffraction pattern of the flank of the cutting edge in each cermet tool), the edge portion where the flank of the cutting edge intersected the rake face was used. The maximum layer thickness was measured, and further, the layer thickness was measured at the flank and rake face at locations 1 mm inward from the edge portion. Table 5 shows the measurement results. Note that the Al—O based amorphous layer and the Al ₂ O
_The thickness of each of the Ti compound layers other than the _three layers showed almost no local variation and showed almost the same value as the target layer thickness.

Further, for the purpose of evaluating the chipping resistance of the cutting edge, the coated cermet tools 1 and 2 of the present invention and the conventional coated cermet tools 1 and 2 were prepared as follows: Work material: JIS S25C round bar, Cutting speed: 350 m / min. Infeed: 1 mm. Feed: 0.25 mm / rev. Cutting time: 20 minutes, dry continuous cutting test of carbon steel under the following conditions: Work material: JIS S25C, 4 longitudinally spaced round bars at regular intervals in the longitudinal direction, Cutting speed: 250 m / min. Infeed: 1 mm. Feed: 0.2 mm / rev. , Cutting time: 15 minutes, dry intermittent cutting test of carbon steel was performed under the following conditions, and the flank wear width of the cutting edge was measured in each cutting test. Table 5 shows the results of these measurements.

[0010]

[Table 1]

[0011]

[Table 2]

[0012]

[Table 3]

[0013]

[Table 4]

[0014]

[Table 5]

[0015]

From the results shown in Table 5, it can be seen that the hard coating layer was formed by forming an Al-O-based amorphous layer containing Ti, Cl and N using an Ar gas-based reaction gas. Inventive coated cermet tools 1 and 2 have a very small local variation even if the thickness of the Al-O-based amorphous layer is increased, and the flank, rake face, and flank of the cutting edge. While the layer thickness at the edge where the rake faces intersect is uniform, a hydrogen-based reaction gas is
Conventional coated cermet tools 1 and 2 formed with a ₂ O ₃ layer
, The thickness of the flank, the rake face and the edge portion is significantly varied. As a result, the coated cermet tools 1 and 2 according to the present invention are characterized in that the Al—O-based amorphous layer forms a hard coating layer. Excellent wear resistance in continuous cutting of steel, combined with excellent adhesion to the compound layer, excellent oxidation resistance and thermal stability equivalent to that of the Al ₂ O ₃ layer, and high hardness It is clear that, in addition to the conventional cermet tools 1 and 2, especially in intermittent cutting, it shows much higher fracture resistance than the conventional coated cermet tools 1 and 2. As described above, the coated cermet tool of the present invention has an Al—O-based amorphous layer constituting the hard coating layer, even if the Al—O-based amorphous layer is thickened, has very little local variation,
Since the interlayer adhesion to the compound layer is also excellent, the Al-O-based amorphous layer has properties equivalent to that of the Al ₂ O ₃ layer. In particular, it exhibits excellent fracture resistance in intermittent cutting and exhibits excellent cutting performance over a long period of time, so that it is possible to satisfactorily cope with FA and labor saving in cutting.

Continuing on the front page (72) Inventor Toshiaki Ueda 1511 Furamagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Inside the Tsukuba Works, Mitsubishi Materials Corporation (72) Inventor ▲ Isao Toshi, 1515 Furusagi, Ishishita-cho, Yuki-gun, Ibaraki Prefecture No. Mitsubishi Tsukuba Works, Mitsubishi Materials Corporation (72) Inventor Yuki Hamaguchi 1511 Furamaki, Ishishita-cho, Yuki-gun, Ibaraki Prefecture Inside Tsukuba Works, Mitsubishi Materials Corporation (56) References JP-A-52-96912 (JP, A) INTERNATIONAL JOR NAL OF Refractory & Hard Metals, UK, VOL 5 [4], p222-228 (58) Fields investigated (Int. Cl. ⁷ , DB name) B23B 27/14 B23P 15/28 C23C 16/30-16/40 C23C 14 / 08

Claims (1)

(57) [Claims] A titanium carbide layer formed by chemical vapor deposition or physical vapor deposition on the surface of a titanium carbonitride-based cermet substrate;
One or more of a Ti compound layer consisting of a nitride layer, a carbonitride layer, an oxide layer, a carbonate layer, a nitrogen oxide layer, and a carbonitride layer; Aluminum: 1-10%, hydrogen: 1
５5%, nitrogen oxides: 16-30%, titanium tetrachloride:
0.05 to 0.7%, Ar: the remainder is formed by chemical vapor deposition using an Ar-based reaction gas having a composition of: Ti: 1 to 15% by weight (mass%) on aluminum oxide; Cl: : 0.005 to 0.1%, and N: 0.001 to 0.1%.
A cutting tool made of a surface-coated cermet having excellent fracture resistance, wherein a hard coating layer composed of -O-based amorphous layer is formed with an average layer thickness of 3 to 20 µm.